?url_ver=Z39.88-2004&rft_id=1993-24&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Constraint+Management+in+Loosely+Coupled+Distributed+Databases&rft.creator=Chawathe%2C+S.&rft.creator=Garcia-Molina%2C+H.&rft.creator=Widom%2C+J.&rft.subject=Data+Integration+and+Mediation&rft.description=We+provide+a+framework+for+managing+integrity+constraints+that+span+multiple+databases+in+loosely+coupled%2C+heterogeneous+environments.+Our+framework+enables+the+formal+description+of+(1)+interfaces+provided+by+a+database+for+the+data+items+involved+in+multi-database+constraints%3B+(2)+strategies+for+monitoring+and+maintaining+multi-database+constraints%3B+(3)+guarantees+regarding+the+consistency+of+multi-database+constraints.+With+our+approach+one+can+define+%22relaxed%22+constraints+that+only+hold+at+certain+times+or+under+certain+conditions.+Such+constraints+appear+often+in+practice+and+cannot+be+handled+effectively+by+conventional%2C+transaction-based+approaches.+We+also+describe+a+toolkit%2C+based+on+our+framework%2C+for+enforcing+constraints+over+heterogeneous+systems.+The+toolkit+includes+a+general-purpose%2C+distributed+constraint+manager+that+can+be+easily+configured+to+a+given+environment+and+constraints.+A+first+version+of+the+toolkit+has+been+implemented+and+is+under+evaluation.&rft.publisher=Stanford+InfoLab&rft.date=1993&rft.type=Techreport&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Filpubs.stanford.edu%3A8090%2F32%2F1%2F1993-24.pdf&rft.identifier=Chawathe%2C+S.+and+Garcia-Molina%2C+H.+and+Widom%2C+J.+(1993)+Constraint+Management+in+Loosely+Coupled+Distributed+Databases.+Technical+Report.+Stanford+InfoLab.+(Publication+Note%3A+Detailed+version+of+papers+appearing+in+ICDE+1996+and+Data+Engg.+Bull.+17(2)%2C+June+1994)&rft.relation=http%3A%2F%2Filpubs.stanford.edu%3A8090%2F32%2F